New-onset psychogenic seizures after surgery for epilepsy

BACKGROUND: The emergence of psychogenic seizures after surgery for epilepsy is not well recognized. OBJECTIVES: To identify the frequency of psychogenic seizures in an 11-year surgical experience and to characterize the patients with this complication. METHODS: Ninety-six patients underwent surgery for epilepsy between 1985 and 1996. The surgical database was reviewed and all patients who experienced postoperative psychogenic seizures were identified. Patients were characterized by sex, age, psychopathologic conditions, full-scale IQ, duration of epilepsy, surgical procedure, and operative complications. Patients were compared with the surgical group as a whole for these variables. SETTING: A comprehensive epilepsy center. RESULTS: Five patients were identified: 3 men and 2 women. Mean full-scale IQ was 73 (range, 66-82). Mean age was 29.8 years (range, 22-36 years). Three patients were diagnosed as having psychosis, 1 with borderline personality disorder and 1 with generalized anxiety. Operations included 4 anterior temporal lobectomies and 1 occipital lobectomy. Two patients experienced operative complications. Compared with the surgical cohort, patients had a higher frequency of preoperative psychopathologic conditions, lower mean full-scale IQ, and a greater occurrence of operative complications. CONCLUSIONS: (1) Patients can develop new-onset psychogenic seizures after surgery for epilepsy. (2) Low full-scale IQ, serious preoperative psychopathologic conditions, and major surgical complications may be risk factors. (3) Atypical postoperative seizures should be evaluated with video electroencephalographic monitoring before concluding that they are epileptic.     

Incidence risk and aetiology of mammary abnormalities in dry ewes in 10 flocks in southern Greece

In a field investigation of 10 flocks in Southern Greece, 3367 dairy ewes were examined twice, in order to estimate the incidence risk and the aetiology of mammary abnormalities during the dry-period. Abnormal secretion, lumps, nodules, diffuse hardness, abscesses and cysts were the abnormalities detected. The cumulative incidence of mammary abnormalities during the dry-period was 5.1% (95% confidence interval: 4.4-5.8%); 47% of the cases detected developed during the first three weeks after cessation of lactation. Despite variation in the flock size, there was no between-flock variation in the risk of a ewe developing mammary abnormalities. Staphylococci (Staphylococcus aureus and coagulase-negative isolates) were the most frequently isolated bacteria from mammary samples; Actinomyces pyogenes, Clostridium perfringens, streptococci and Escherichia coli were also isolated. Resistance was encountered among the staphylococcal isolates.     

Gemfibrozil treatment increases low-density lipoprotein particle size in Type 2 diabetes mellitus but does not alter in vitro oxidizability

The aim of this study was to determine the effect of the lipid modifying agent gemfibrozil on lipid and coagulation risk factors in patients with Type 2 diabetes mellitus (Type 2 DM). Twenty-six subjects with Type 2 DM and dyslipidaemia were treated for 24 weeks with either gemfibrozil 600 mg orally twice daily or placebo in a double-blind randomized trial. Lipid profiles, fibrinogen, Factor VII, and plasminogen activator inhibitor-1 (PAI-1) were measured by routine laboratory methods. Low density lipoprotein (LDL) size was determined by gradient gel electrophoresis and the resistance of LDL to copper-induced oxidation was assessed by measuring absorbance at 234 nm. Gemfibrozil significantly reduced total cholesterol (-0.9 (-0.48, -1.32) mmol l(-1); p < 0.05) and triglycerides (-2.7 (-1.55, -1.35) mmol l(-1); p < 0.001) vs placebo. The fall in triglyceride was reflected by a fall in VLDL cholesterol levels in the gemfibrozil treated group vs placebo (-1.31 mmol l(-1); p < 0.001). LDL-cholesterol level did not change but LDL particle size increased by 0.5 nm (0.01, 0.93); P < 0.02. The increase in particle size was inversely correlated with the change of triglyceride level (r = -0.79, p < 0.0001) but did not result in any reduction of susceptibility to copper-induced oxidation. There were no significant changes in the coagulation parameters studied. Because of its ability to correct the lipid abnormalities associated with Type 2 DM particularly hypertriglyceridaemia, gemfibrozil provides a useful therapeutic option in the management of diabetic dyslipidaemia but it does not alter in vitro oxidizability of LDL.     

Reduced performance of male and female athletes at 580 m altitude

Patients with craniocervical mandibular (TMD) disorders can present with tinnitus as a primary or secondary complaint. The embryology and functional anatomy of the middle ear, temporomandibular joint, muscles of mastication and associated tendons, ligaments, blood vessels, nerves and lymphatics was found to be helpful in establishing etiologic concepts which relate tinnitus to these temporomandibular disorders. In addition to etiologic concepts, treatment modalities are described. The authors relate their experiences as well as those of others with different patient populations.     

Changes in the signalling status of the small GTP-binding proteins Rac and Rho do not influence insulin-stimulated hexose transport

Post-receptor signalling molecules that convey the signal from the activated insulin receptor to the actual process of Glut4 translocation and hexose uptake are poorly understood. Various studies have suggested a requirement of the lipid kinase phosphatidylinositol-3 kinase (PI3-kinase) in this process. PI3kinase regulates the activation status of the small GTP-binding protein Rac which, in turn, is able to activate another G-protein Rho. Rac and Rho are known to regulate the structure of the membrane- and cytoplasmic actin-cytoskeleton. We have examined whether Rac and Rho transfer the signals generated by PI3kinase towards insulin-stimulated hexose uptake. For that purpose, we expressed in 3T3-L1 adipocytes the dominant-negative mutant of RacN17 using vaccinia virus-mediated gene transfer. The expression levels of the RacN17 protein were monitored by Western blotting. The abrogation of endogenous Rac signalling by expression of RacN17 was inferred from the observed loss of arachidonic acid release in response to insulin. Basal and insulin-stimulated hexose transport were not affected by expression of the RacN17 mutant. A possible contribution of Rho.GTP to stimulation of hexose uptake was examined by pre-incubation of adipocytes with lysophosphatidic acid (LPA). We observed a profound effect of LPA on the structure of the cytoskeleton and on the phosphorylation of Focal Adhesion Kinase (p125FAK), indicating that 3T3-L1 adipocytes respond to LPA and that Rho was activated by LPA. However, no effect was detected on the basal or on the insulin-stimulated hexose transport. We conclude that Rac and Rho are unlikely to be involved in insulin-stimulated hexose transport, suggesting a possible contribution of other signalling pathways, downstream of PI3kinase to this process.     

Comparison of nested PCR with immunofluorescent-antibody assay for detection of Ehrlichia canis infection in dogs treated with doxycycline

A partial 16S rRNA gene was amplified in Ehrlichia canis-infected cells by nested PCR. The assay was specific and did not amplify the closely related Ehrlichia chaffeensis, Ehrlichia muris, Neorickettsia helminthoeca, and SF agent 16S rRNA genes. The assay was as sensitive as Southern hybridization, detecting as little as 0.2 pg of E. canis DNA. By this method, all blood samples from four dogs experimentally infected with E. canis were positive as early as day 4 postinoculation, which was before or at the time of seroconversion. One hundred five blood samples from dogs from Arizona and Texas (areas of E. canis endemicity) and 30 blood samples from dogs from Ohio (area of E. canis nonendemicity) were examined by nested PCR and immunofluorescent-antibody (IFA) test. Approximately 84% of dogs from Arizona and Texas had been treated with doxycycline before submission of blood specimens. Among Arizona and Texas specimens, 46 samples were PCR positive (44%) and 80 were IFA positive (76%). Forty-three of 80 IFA-positive samples (54%) were PCR positive, and 22 of 25 IFA-negative samples (88%) were negative in the nested PCR. None of the Ohio specimens were IFA positive, but 5 specimens were PCR positive (17%). Our results indicate that the nested PCR is highly sensitive and specific for detection of E. canis and may be more useful in assessing the clearance of the organisms after antibiotic therapy than IFA, especially in areas in which E. canis is endemic.     

1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine as a substrate of cytochrome P450 2D6: allosteric effects of NADPH-cytochrome P450 reductase

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), a neurotoxin that produces Parkinsonism symptoms in man, has been examined as a substrate of recombinant human cytochrome P450 2D6. When cumene hydroperoxide is used as an oxygen and electron donor, a single product is formed, identified as 4-phenyl-1,2,3,6-tetrahydropyridine. The K(m) for formation of this product (130 microM) is in agreement with the dissociation constants for MPTP binding to the enzyme determined by optical and nuclear magnetic resonance (NMR) spectroscopy. When the reaction is carried out with nicotinamide adenine dinucleotide phosphate (reduced) (NADPH) and recombinant human NADPH-cytochrome P450 reductase, a second product, identified as 1-methyl-4-(4'-hydroxyphenyl)-1,2,3,6-tetrahydropyridine, is formed in addition to 4-phenyl-1,2,3,6-tetrahydropyridine. The K(m) values for formation of these two products are 19 microM and 120 microM, respectively. Paramagnetic relaxation experiments have been used to measure distances between the protons of bound MPTP and the heme iron, and these have been used to construct models for the position and orientation of MPTP in the active site. For the cytochrome alone, a single mode of binding was observed, with the N-methyl close to the heme iron in a position appropriate for the observed N-demethylation reaction. In the presence of the reductase, the data were not consistent with a single mode of binding but could be explained by the existence of two alternative orientations of MPTP in the active site. One of these, characterized by a dissociation constant of 150 microM, is essentially identical to that observed in the absence of the reductase. In the second, which has a K(d) of 25 microM, the MPTP is oriented so that the aromatic ring is close to the heme iron, in a position appropriate for p-hydroxylation leading to the formation of the product seen only in the presence of the reductase. In the case of codeine, another substrate for cytochrome P450 2D6, the addition of reductase had no effect on the nature of the product formed, the dissociation constant, or the orientation in the binding site. These observations show that NADPH-cytochrome P450 reductase has an allosteric effect on the active site of cytochrome P450 2D6 that affects the binding of some substrates but not others.